What's the difference between effort-based, amount-based, and percentage-based performance measures?

Performance measures that are based on currency
values are amount-based. Examples are, actual revenue and actual raw
cost.

Performance measures that are based on percentages
are percentage-based. Examples are, actual margin percentage and actual
nonbillable cost percentage.

Note

KPIs that are percentage-based can be tracked at the
task, resource, and project levels.

What happens if I use period-to-date amount-based measures for
large projects?

Period-to-date amount-based measures use the
same threshold values for all phases of the project. This may result
in a spike in the key performance indicator (KPI) values if the amounts
used to calculate the KPI values vary widely throughout the project.
To avoid this problem, consider using different sets of threshold
values for amount-based KPIs defined in small and large
projects.